<?php

if (! defined ( 'BASEPATH' ))
	exit ( 'No direct script access allowed' );
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------


/**
 * Common Functions
 *
 * Loads the base classes and executes the request.
 *
 * @package		CodeIgniter
 * @subpackage	codeigniter
 * @category	Common Functions
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/
 */

// ------------------------------------------------------------------------


/**
 * Determines if the current version of PHP is greater then the supplied value
 *
 * Since there are a few places where we conditionally test for PHP > 5
 * we'll set a static variable.
 *
 * @access	public
 * @param	string
 * @return	bool	TRUE if the current version is $version or higher
 */
if (! function_exists ( 'is_php' )) {
	function is_php($version = '5.0.0') {
		static $_is_php;
		$version = ( string ) $version;
		
		if (! isset ( $_is_php [$version] )) {
			$_is_php [$version] = (version_compare ( PHP_VERSION, $version ) < 0) ? FALSE : TRUE;
		}
		
		return $_is_php [$version];
	}
}

// ------------------------------------------------------------------------


/**
 * Tests for file writability
 *
 * is_writable() returns TRUE on Windows servers when you really can't write to
 * the file, based on the read-only attribute.  is_writable() is also unreliable
 * on Unix servers if safe_mode is on.
 *
 * @access	private
 * @return	void
 */
if (! function_exists ( 'is_really_writable' )) {
	function is_really_writable($file) {
		// If we're on a Unix server with safe_mode off we call is_writable
		if (DIRECTORY_SEPARATOR == '/' and @ini_get ( "safe_mode" ) == FALSE) {
			return is_writable ( $file );
		}
		
		// For windows servers and safe_mode "on" installations we'll actually
		// write a file then read it.  Bah...
		if (is_dir ( $file )) {
			$file = rtrim ( $file, '/' ) . '/' . md5 ( mt_rand ( 1, 100 ) . mt_rand ( 1, 100 ) );
			
			if (($fp = @fopen ( $file, FOPEN_WRITE_CREATE )) === FALSE) {
				return FALSE;
			}
			
			fclose ( $fp );
			@chmod ( $file, DIR_WRITE_MODE );
			@unlink ( $file );
			return TRUE;
		} elseif (! is_file ( $file ) or ($fp = @fopen ( $file, FOPEN_WRITE_CREATE )) === FALSE) {
			return FALSE;
		}
		
		fclose ( $fp );
		return TRUE;
	}
}

// ------------------------------------------------------------------------


/**
 * Class registry
 *
 * This function acts as a singleton.  If the requested class does not
 * exist it is instantiated and set to a static variable.  If it has
 * previously been instantiated the variable is returned.
 *
 * @access	public
 * @param	string	the class name being requested
 * @param	string	the directory where the class should be found
 * @param	string	the class name prefix
 * @return	object
 */
if (! function_exists ( 'load_class' )) {
	function &load_class($class, $directory = 'libraries', $prefix = 'CI_') {
		static $_classes = array ();
		
		// Does the class exist?  If so, we're done...
		if (isset ( $_classes [$class] )) {
			return $_classes [$class];
		}
		
		$name = FALSE;
		
		// Look for the class first in the native system/libraries folder
		// thenin the local application/libraries folder
		foreach ( array (BASEPATH, APPPATH ) as $path ) {
			if (file_exists ( $path . $directory . '/' . $class . '.php' )) {
				$name = $prefix . $class;
				
				if (class_exists ( $name ) === FALSE) {
					require ($path . $directory . '/' . $class . '.php');
				}
				
				break;
			}
		}
		
		// Is the request a class extension?  If so we load it too
		if (file_exists ( APPPATH . $directory . '/' . config_item ( 'subclass_prefix' ) . $class . '.php' )) {
			$name = config_item ( 'subclass_prefix' ) . $class;
			
			if (class_exists ( $name ) === FALSE) {
				require (APPPATH . $directory . '/' . config_item ( 'subclass_prefix' ) . $class . '.php');
			}
		}
		
		// Did we find the class?
		if ($name === FALSE) {
			// Note: We use exit() rather then show_error() in order to avoid a
			// self-referencing loop with the Excptions class
			exit ( 'Unable to locate the specified class: ' . $class . '.php' );
		}
		
		// Keep track of what we just loaded
		is_loaded ( $class );
		
		$_classes [$class] = new $name ();
		return $_classes [$class];
	}
}

// --------------------------------------------------------------------


/**
 * Keeps track of which libraries have been loaded.  This function is
 * called by the load_class() function above
 *
 * @access	public
 * @return	array
 */
if (! function_exists ( 'is_loaded' )) {
	function is_loaded($class = '') {
		static $_is_loaded = array ();
		
		if ($class != '') {
			$_is_loaded [strtolower ( $class )] = $class;
		}
		
		return $_is_loaded;
	}
}

// ------------------------------------------------------------------------


/**
 * Loads the main config.php file
 *
 * This function lets us grab the config file even if the Config class
 * hasn't been instantiated yet
 *
 * @access	private
 * @return	array
 */
if (! function_exists ( 'get_config' )) {
	function &get_config($replace = array()) {
		static $_config;
		
		if (isset ( $_config )) {
			return $_config [0];
		}
		
		// Is the config file in the environment folder?
		if (! defined ( 'ENVIRONMENT' ) or ! file_exists ( $file_path = APPPATH . 'config/' . ENVIRONMENT . '/config.php' )) {
			$file_path = APPPATH . 'config/config.php';
		}
		
		// Fetch the config file
		if (! file_exists ( $file_path )) {
			exit ( 'The configuration file does not exist.' );
		}
		
		require ($file_path);
		
		// Does the $config array exist in the file?
		if (! isset ( $config ) or ! is_array ( $config )) {
			exit ( 'Your config file does not appear to be formatted correctly.' );
		}
		
		// Are any values being dynamically replaced?
		if (count ( $replace ) > 0) {
			foreach ( $replace as $key => $val ) {
				if (isset ( $config [$key] )) {
					$config [$key] = $val;
				}
			}
		}
		
		return $_config [0] = & $config;
	}
}

// ------------------------------------------------------------------------


/**
 * Returns the specified config item
 *
 * @access	public
 * @return	mixed
 */
if (! function_exists ( 'config_item' )) {
	function config_item($item) {
		static $_config_item = array ();
		
		if (! isset ( $_config_item [$item] )) {
			$config = & get_config ();
			
			if (! isset ( $config [$item] )) {
				return FALSE;
			}
			$_config_item [$item] = $config [$item];
		}
		
		return $_config_item [$item];
	}
}

// ------------------------------------------------------------------------


/**
 * Error Handler
 *
 * This function lets us invoke the exception class and
 * display errors using the standard error template located
 * in application/errors/errors.php
 * This function will send the error page directly to the
 * browser and exit.
 *
 * @access	public
 * @return	void
 */
if (! function_exists ( 'show_error' )) {
	function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered') {
		$_error = & load_class ( 'Exceptions', 'core' );
		echo $_error->show_error ( $heading, $message, 'error_general', $status_code );
		exit ();
	}
}

// ------------------------------------------------------------------------


/**
 * 404 Page Handler
 *
 * This function is similar to the show_error() function above
 * However, instead of the standard error template it displays
 * 404 errors.
 *
 * @access	public
 * @return	void
 */
if (! function_exists ( 'show_404' )) {
	function show_404($page = '', $log_error = TRUE) {
		$_error = & load_class ( 'Exceptions', 'core' );
		$_error->show_404 ( $page, $log_error );
		exit ();
	}
}

// ------------------------------------------------------------------------


/**
 * Error Logging Interface
 *
 * We use this as a simple mechanism to access the logging
 * class and send messages to be logged.
 *
 * @access	public
 * @return	void
 */
if (! function_exists ( 'log_message' )) {
	function log_message($level = 'error', $message, $php_error = FALSE) {
		static $_log;
		
		if (config_item ( 'log_threshold' ) == 0) {
			return;
		}
		
		$_log = & load_class ( 'Log' );
		$_log->write_log ( $level, $message, $php_error );
	}
}

// ------------------------------------------------------------------------


/**
 * Set HTTP Status Header
 *
 * @access	public
 * @param	int		the status code
 * @param	string
 * @return	void
 */
if (! function_exists ( 'set_status_header' )) {
	function set_status_header($code = 200, $text = '') {
		$stati = array (200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content', 

		300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Found', 304 => 'Not Modified', 305 => 'Use Proxy', 307 => 'Temporary Redirect', 

		400 => 'Bad Request', 401 => 'Unauthorized', 403 => 'Forbidden', 404 => 'Not Found', 405 => 'Method Not Allowed', 406 => 'Not Acceptable', 407 => 'Proxy Authentication Required', 408 => 'Request Timeout', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Long', 415 => 'Unsupported Media Type', 416 => 'Requested Range Not Satisfiable', 417 => 'Expectation Failed', 

		500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Timeout', 505 => 'HTTP Version Not Supported' );
		
		if ($code == '' or ! is_numeric ( $code )) {
			show_error ( 'Status codes must be numeric', 500 );
		}
		
		if (isset ( $stati [$code] ) and $text == '') {
			$text = $stati [$code];
		}
		
		if ($text == '') {
			show_error ( 'No status text available.  Please check your status code number or supply your own message text.', 500 );
		}
		
		$server_protocol = (isset ( $_SERVER ['SERVER_PROTOCOL'] )) ? $_SERVER ['SERVER_PROTOCOL'] : FALSE;
		
		if (substr ( php_sapi_name (), 0, 3 ) == 'cgi') {
			header ( "Status: {$code} {$text}", TRUE );
		} elseif ($server_protocol == 'HTTP/1.1' or $server_protocol == 'HTTP/1.0') {
			header ( $server_protocol . " {$code} {$text}", TRUE, $code );
		} else {
			header ( "HTTP/1.1 {$code} {$text}", TRUE, $code );
		}
	}
}

// --------------------------------------------------------------------


/**
 * Exception Handler
 *
 * This is the custom exception handler that is declaired at the top
 * of Codeigniter.php.  The main reason we use this is to permit
 * PHP errors to be logged in our own log files since the user may
 * not have access to server logs. Since this function
 * effectively intercepts PHP errors, however, we also need
 * to display errors based on the current error_reporting level.
 * We do that with the use of a PHP error template.
 *
 * @access	private
 * @return	void
 */
if (! function_exists ( '_exception_handler' )) {
	function _exception_handler($severity, $message, $filepath, $line) {
		// We don't bother with "strict" notices since they tend to fill up
		// the log file with excess information that isn't normally very helpful.
		// For example, if you are running PHP 5 and you use version 4 style
		// class functions (without prefixes like "public", "private", etc.)
		// you'll get notices telling you that these have been deprecated.
		if ($severity == E_STRICT) {
			return;
		}
		
		$_error = & load_class ( 'Exceptions', 'core' );
		
		// Should we display the error? We'll get the current error_reporting
		// level and add its bits with the severity bits to find out.
		if (($severity & error_reporting ()) == $severity) {
			$_error->show_php_error ( $severity, $message, $filepath, $line );
		}
		
		// Should we log the error?  No?  We're done...
		if (config_item ( 'log_threshold' ) == 0) {
			return;
		}
		
		$_error->log_exception ( $severity, $message, $filepath, $line );
	}
}

// --------------------------------------------------------------------


/**
 * Remove Invisible Characters
 *
 * This prevents sandwiching null characters
 * between ascii characters, like Java\0script.
 *
 * @access	public
 * @param	string
 * @return	string
 */
if (! function_exists ( 'remove_invisible_characters' )) {
	function remove_invisible_characters($str, $url_encoded = TRUE) {
		$non_displayables = array ();
		
		// every control character except newline (dec 10)
		// carriage return (dec 13), and horizontal tab (dec 09)
		

		if ($url_encoded) {
			$non_displayables [] = '/%0[0-8bcef]/'; // url encoded 00-08, 11, 12, 14, 15
			$non_displayables [] = '/%1[0-9a-f]/'; // url encoded 16-31
		}
		
		$non_displayables [] = '/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]+/S'; // 00-08, 11, 12, 14-31, 127
		

		do {
			$str = preg_replace ( $non_displayables, '', $str, - 1, $count );
		} while ( $count );
		
		return $str;
	}
}

/* End of file Common.php */
/* Location: ./system/core/Common.php */